but my original point is if there is yellowing of the angel eyes
it would not matter which vendor or ebay kit is used
it would be a function of the UV emitted by the HID bulbs
irrespective of where you got the kit.
i know i've had one headlight replaced
and when i reinstalled the HID kits
the newer one is much whiter than the old headlight

Age, time, water, and suns UV causes yellowing also, I do not think the HIDs accelerate even by 5% as much as everything else that takes into play, your headlight replaced faced much more sunlight, water, and timing effects, can you agree with that or no?